In railcars, for example, an accommodation recess which accommodates instruments necessary to be periodically checked is formed in a car body, and a lid body (a closing plate) which covers an opening of the accommodation recess is locked so that a third party cannot open carelessly has been known (for example, refer to Patent Documents 1 to 3).
A locking apparatus for latching such a lid body to the car body is desired to be configured so that its locked state is easily visible only at a glance. In addition, since frequency of opening and closing is often, it is desired to be configured so that unlocking is easy when, for example, a maintenance operator performs the unlocking, but person other than the operator cannot unlock freely.